For the first time in modern history, an Arab despot is being held to account by his own people. From a hospital bed in a courtroom cage, Hosni Mubarak, the Egyptian dictator ousted in February’s popular uprising, pleaded not guilty to charges of conspiring to kill protesters and abusing his powers for personal gain. On trial with him are his sons, Alaa and Gamal, Habib al-Adly, the ex-interior minister, and six former security officials. In a region where an untouchable elite had until six months ago been protected by a cloak of impunity, this is a remarkable turnaround.

Mr Mubarak has much to answer for. Not only were 850 protesters killed in the demonstrations that led to his departure. For three suffocating decades, he presided over a country in which draconian state-of-emergency laws were routinely used to justify killings and torture; and in which millions were consigned to penury and economic hopelessness while a kleptocratic elite gorged itself on Egypt’s national wealth. The catharsis of seeing Mr Mubarak forced to account for this grim past is the least the victims deserve.

Egypt’s interim leadership faced heavy external pressure not to try Mr Mubarak. That the fallen pharaoh has been forced to stand trial sends an unambiguous message – not only to those still risking their lives in the pursuit of freedom, but also to the other Arab autocrats who oppress them. Western countries that spent 30 years turning a blind eye to Mr Mubarak’s abuses may feel uncomfortable watching a former ally on trial but they must also recognise their complicity.